In the orientation of autonomous mobile units like, for example, remote exploration probes, units that operate in danger zones, self-propelled industrial vacuum cleaners, transport vehicles and self-propelled robots, the problem arises that they must get their own impression of their environment. To that end, such an apparatus must construct a reliable map or its work environment and be simultaneously able to localize itself at any time on the basis of this map. It is thereby to be noted that an optimally fast evaluation and an optimally fast construction of this map can be required dependent on the speed of movement of such an apparatus. A practical method for the construction of such a map and for orientation of such a self-propelled mobile unit in an unknown environment is comprised therein that the unit constructs a two-dimensional grid of its environs and provides individual cells of this grid with degree of occupancy values. The degree of occupancy values assigned to a grid cell represent the occurrence of obstacles in the environment. Methods of this species are known from the Prior Art and shall form the basis for the present invention.
U.S. Pat. No. 5,006,788 discloses a basic method for the construction of cellularly structured environment maps that are provided with degree of occupancy values for representing obstacles. German Patent 44 08 329 C2 discloses recites a method with which the orientation of such a mobile unit within such a grid map can be improved, in that a coordinate reference point under the discretization provided by the map is defined in that a specific point of an autonomous mobile unit within an initial cell is defined as coordinate reference point. German Patent 4408 328 A1 recites another orientation method for autonomous mobile units within a grid raster wherein sensor properties such as blind areas and maximum distances to obstacles are co-involved for the evaluation of the map.